Steam-superheater.



E. H. POSTER.

' STEAM SUPERHEATER.

APPLICATION FILED MAY 15, 19077 Patented June 10, 1913.

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E. H. FOSTER.

STEAM SUPBRHEATER.

APPLIOATION IILBD my 15, 1907.

1,964,309., Patented June 10,1913.

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PATENT OFFICE.

ERNEST H. FOSTER, OF NEW YORK, Y.

STEAM-SUPEBHEATEB.

' Specification of Letters Patent.

Patented June 10, 1913.

Application filed May 15, 1907. Serial No. 373,755.

To all whom it may concern:

Be it known that I,E1mns'r H. FOSTER, a

citizen of the United States, residing at New York, in the county and State of New York, 5 have invented certainnew and useful Improvements in Steam-Superheaters, of which the following is a specification, reference being had to the drawings, which accompany and form a part of the same.

The invention which forms the subject of my present application for Letters Patent pertains to boilers of the so-called vertical tube class, of which the well known Stirling boiler may, beregarded as typical, and consists in the combination with such a boiler of a U-tube superheater supported within the heating chamber in anovel manner.

In arranging a superheater of this kind in connection 'with a boiler, it is desirable to utilize the boiler heating chamber of the setting as the location of the superheater, the latter thereby receiving heat from the gases which also heat the boiler. In such cases, however, some means of supportfor the superheater must be, of course, provided, and this presents serious practical difiiculties in connection with boilers of the Stirling type, mainly by reason of the width of the boiler setting. g

It is obviously desirable that the superheater be maintained in fixed relation to the boiler itself, but the destructive effect of the hot gases on any ordinary supports for the purpose introduced into the path of the furnace gases, renders their employment objec tionable. Furthermore, such supports would have nothing to rest on, but the heating surface of the boiler, an arrangement which is seriously inconvenient because of the increased difiiculty of removing boiler tubes when necessary, and because of the need of strengthening parts which are not intended to carry weights. To avoid these and other objections incident to supporting the superheaters from the heating surface of the boiler, various expedients have been resorted to. In some instances the headers have been supported or embedded inthe walls of the furnace chamber, the tubes projecting laterally fr such headers into spaces between the ban s of boiler tubes, as shown in the U. S. patent to Sneddon, No. 716,297;

' or vertically from'the headers, as shown in 55 British patent to McPhail, No. 20,057 of 1900. Another'plan has been to arrange the headers horizontally above the boiler heating chamber. In these arrangements the headers are readily accessible for inspecpractical considerations,but this advantage is more than offset by decrease of eflinot utilized for heating purposes.

My present invention provides a plan 'cated, as in other types of boiler, entirely within the boiler heating chamber, is so supported therein in fixed relation to the boiler, as to overcome all of the objections noted above. According to this plan the heater tubes are connected, serve as the superheater supports, thus avoiding the employment of special supporting devices, which would be injured by the high temperature to which they must of necessity be subjected. Practically the entire space available within the boiler heating chamber can thus be utilized for superheating purposes, and the superheater can be drained with the utmost facility.

The nature of the invention by which the above advantages, among others, are secured, will be more readily understood in connection with the accompanying drawings, in which is illustrated the preferred arrangement and construction of a superheater for a common type of vertical tube boiler.

Figure 1 is a central longitudinal section through the boiler and setting, showing the superheater in position. Fig. 2 is a transverse section, substantially on line 11-11 showing one section and part of another of a battery of boilers. Fig. 3 is a detail sectional view showing the preferred type of superheater element employed.

Figs. 1 and 2 of the drawing will be seen well known Stirling boiler constructed and supported in the usual and well known manner. The boiler comprises three upper or steam drums A, B and 0 connected with a lower water drum' D by front, middle and rear groups or banks of water tubes designated by a, b, and 0, respectively, all located within the boiler heating chamber formed by the usual setting E. These banks of tubes are in series, as regards the passage of the furnace gases, that is, the gases flow tion, repairs, etc.,a feature demanded by to be the conventional illustration of the and extend the tubes downwardly'into the I ciency due to the fact that the headers are whereby the entire superheater, while loheaders themselves and to which the superof the furnace will be directed against the boiler elements in the most effective manner for heating the latter.

The superheater is shown at S, and is located within the setting, near the to of the heating chamber and between the rst and second banks of tubes at and b, and extends transversely across the space between said banks. The superheater is one of the kind well known in the art as a U-tube superheater, and consists of a plurality of U-shaped tubes or elements 8, connected at their ends with inlet and outlet headers H and H, respectively, and extending upwardly from the same. The headers are, in turn, connected with the boiler and with theservice steam pipe, respectively, in the ordinary way, that is to say, the headers project through the wall of the setting at one side of the boiler, as shown in Fig. 2, and are connected by a pipe P to the middle drum B, and to the service main, not shown, by a pipe P. The headers are supported by U-shaped hangers h, preferably embedded in the brick-work of the setting and depending from the metal I-beams i, which in the boiler settings of this kind extend transversely to and are supported immediately under the drums A and C, and are shown, in Fig. 1, one partially inclosed by a side wall of the set-ting and the other wholly in.- closed by the partition wall between the two sets of the battery of boilers. These I-beams, as shown by the conventional illustration adopted and as is Well known, constitute a rigid means upon which the boiler may be supported, so that the superheater may thus be maintained in fixed relation to-the boiler,

with the result that there is no relative.

movement between the two which would cause the joints of thesteam supply pipe P to be impaired.

Any approved type of superheater tubes may be employed, but I prefer that shown in Fig. 3. In that form a steel foundation tube t is employed, covered with metal rings r, preferably tapered and of cast iron shrunk in place, forming a covering which eifectively protects the foundation tube. The corrugations produced by the rings largely constant de noeaeoe I increase the, total heating surface, while the relatively large amount of metal, holding as it does, a large amount of heat, presents sudden cooling of the superheater and thus insures, within certain limits, a more or less cc of so erheat. Inside the tube at is a emf, maintained centrally in the tube by any suitable means, as for example, the lugs or bosses 1, arranged spirally on the filler, the latter is closed at one or both sides (not shown), so that the steam is confined to the annular passage around the same. The surface of the steam exposed to the heat is thus made very large relative to its volume.

What I claim as my inventionisz- 1. The combination with a water tube boiler of the vertical type, and the boiler set ting including vertical walls, of metallic hangers embedded in said walls, oppositely disposed horizontal headers having end portions entering said walls and hung in said hangers, and vertically extending U-shaped superheater tubes connected to the respective headers and extending upwardly therefrom.

2. The combination with a water tube boiler of the vertical tube type, and the boiler setting including vertical walls, of metallic beams embedded in said walls,

hangers depending from said beams, horizontal headers having end portions entering thewalls and hung in said hangers, vertically extending U-shaped superheater tubes connected to the respective headers, and extending upwardly therefrom, said headers and tubes being directly in the path of the furnace gases.

3. The combination with a "Stirling boiler as herein described, comprising upper drums A, B, and G, a lower drum D connected by water tubes arranged ina plurality of banks, and a setting E, of metal beams z' in the walls of the setting and extending transversely to and immediately beneath, the upper drums A and C of asuperheater lo cated within the boiler setting, comprising headers arranged horizontally and transversely in the path of the furnace gases, and upwardly extending superheating tubes connecting the headers, hangers depending from the said beams z' and supporting the headers, and means for conveylng steam from an upper drum to one of the headers.

ERNEST H. FOSTER. Witnesses:

S. S. DUNBAM, M. Lawson Drnn. 

